Astronomer Triggers Public’s Online Search for Overlapping Galaxies

Dec 20, 2007

Armchair astronomers using the galaxyzoo.org Web site have identified more than 500 overlapping galaxies in the local Universe when astronomers had previously only known of 20 such systems.

“This is the best Christmas present our users could hope for!” said Dr. Chris Lintott of Oxford University, a member of the galaxyzoo.org team. “Overlapping galaxies are useful because they enable us to study the dust in each system. Dust grains play a crucial role in the evolution of galaxies and how we see them - the presence of such dust is critical for star formation.”

Visitors to www.galaxyzoo.org get to see stunning images of galaxies. By classifying some of these images, visitors are helping astronomers to understand the structure of the universe. The new digital images were taken using the robotic Sloan Digital Sky Survey telescope in New Mexico.

Each of the 500+ overlapping galaxies was discovered by a member of the public signed up to the galaxyzoo.org forum where armchair astronomers can compare notes on the images of galaxies they have seen and classified using the website. The search for overlapping galaxies was led by Dr. William Keel, professor of astronomy at The University of Alabama. Keel wrote on the forum asking people to look out for suitable systems.

“The thousands of GalaxyZoo users have now found almost 700 such pairs, going much deeper into space than our earlier searches,” Keel said. “With so many to select from, we can now examine how the dust content of galaxies changes with the galaxy's type and brightness. This work should lead to comparison with incoming Hubble data on galaxies in the early Universe, so we can trace the history of cosmic dust with a single technique. This matters because so much starbirth is dust-shrouded, making it crucial to understand how to compensate for this in our calculations.”

Astronomers have been awarded five night’s use of the WIYN telescope on Kitt Peak, Arizona, to take a closer look at the overlapping galaxies identified by the Galaxy Zoo volunteers. The WIYN telescope is one of the largest in the Northern hemisphere and one of the most advanced in the world. This work will begin on April 25.

“We are expecting to get some spectacular images from our Arizona nights but, with the first set of science papers on Galaxy Zoo coming out very soon, we still need more volunteers to visit galaxyzoo.org,” said Lintott. “Even if you’ve visited the site before, please come back and classify some more galaxies in between mouthfuls of turkey and Christmas pudding as we need your help to confirm our results, results which could have a profound impact on our models of the universe.”

The Galaxy Zoo team includes scientists from the University of Oxford, the University of Portsmouth, Johns Hopkins University, and Fingerprint Digital Media of Belfast. Galaxyzoo.org has more than 110,000 users who have viewed more than 30 million images between them. The work on overlapping galaxies has involved the Galaxy Zoo team and astronomers from UA and the Space Telescope Science Institute in Baltimore.

A spectacular Hubble image of an overlapping galaxy, NGC3314, can be viewed at tinyurl.com/2poab5 .

Related Stories

Astronomers at the Space Telescope Science Institute and the Johns Hopkins University, both in Baltimore, Maryland, have created a new master catalog of astronomical objects called the Hubble Source Catalog. ...

When the Large Synoptic Survey Telescope begins in 2022 to image the entire southern sky from a mountaintop in Chile, it will produce the widest, deepest and fastest views of the night sky ever observed – ...

Every year, NASA's Chandra X-ray Observatory looks at hundreds of objects throughout space to help expand our understanding of the Universe. Ultimately, these data are stored in the Chandra Data Archive, ...

Imagine a stadium filled with people. With everyone is in their seats, waiting for the game to begin, there is an undercurrent of noise. A few words between friends, the scuffle of shoes, the creak of a chair. ...

(Phys.org) —A team of astronomers led by Dr David Pinfield at the University of Hertfordshire have discovered two of the oldest brown dwarfs in the Galaxy. These ancient objects are moving at speeds of ...

Recommended for you

Designed to detect the fossil radiation of the universe, the Planck satellite, working in tandem with Herschel, can also help to understand the macrostructure of the universe. A just-published experimental ...

A scene of jagged fiery peaks, turbulent magma-like clouds and fiercely hot bursts of bright light. Although this may be reminiscent of a raging fire or the heart of a volcano, it actually shows a cold cosmic ...

By combining observations of the distant Universe made with ESA's Herschel andPlanck space observatories, cosmologists have discovered what could be the precursors of the vast clusters of galaxies that we ...

Stars form when gravity pulls together material within giant clouds of gas and dust. But gravity isn't the only force at work. Both turbulence and magnetic fields battle gravity, either by stirring things ...

Luke Skywalker's home in "Star Wars" is the desert planet Tatooine, with twin sunsets because it orbits two stars. So far, only uninhabitable gas-giant planets have been identified circling such binary stars, ...